1. Field of the Invention
The present invention relates to a liquid jetting apparatus which jets liquid.
2. Description of the Related Art
There have been known liquid jetting apparatuses, each of which include a liquid jetting head having a liquid jetting surface on which a plurality of nozzles are open to jet the liquid and a wiper which wipes the liquid adhered to the liquid jetting surface. Each of the liquid jetting apparatuses is usually configured such that the wiper is moved in an intersecting direction with respect to the liquid jetting surface which intersects or crosses the liquid jetting surface (hereinafter referred to as “direction intersecting the surface”), thereby making it possible for the wiper to approach to or separate from the liquid jetting surface. Among the liquid jetting apparatuses, there is a liquid jetting apparatus in which a cam mechanism is used as a driving mechanism for driving the wiper, in the direction intersecting the surface, to approach to the liquid jetting surface.
For example, Japanese Patent Application laid-open No. 2005-246929 discloses an ink-jet printer which jets ink on a recording paper sheet to record an image etc., as the liquid jetting apparatus having the wiper. In the ink jet printer described in Japanese Patent Application laid-open No. 2005-246929, an end portion of the wiper makes contact with a front end portion of a cam follower which is engaged with a cam groove of a rotary cam. A cam surface, of the cam groove, which comes into contact with the cam follower is constructed of a surface parallel to the liquid jetting surface and a raised portion which continues to the surface parallel to the liquid jetting surface in a rotating direction of the rotary cam and is raised with respect to the surface parallel to the liquid jetting surface. In a case that the cam follower is brought in contact with the surface, of the cam surface, which is parallel to the liquid jetting surface, the wiper is away from the liquid jetting surface. In a case that the cam follower is separated from the surface parallel to the liquid jetting surface by rotation of the rotary cam to be pushed and moved upward while being brought in contact with the raised portion, the wiper is also pushed and moved upward by the cam follower to come into contact with the liquid jetting surface in accordance with the movement of the cam follower. As described above, in the ink-jet printer described in Japanese Patent Application laid-open No. 2005-246929, the wiper is directly driven by the rotary cam.
In the ink-jet printer as described above, the cam follower gradually goes up a sloped surface of the raised portion of the cam surface in the process in which the wiper separated from the liquid jetting surface approaches to the liquid jetting surface. In this situation, not only the force generated in a direction in which the wiper approaches to the liquid jetting surface but also the force generated in a tangential direction with respect to a rotating path of the rotary cam is applied to a base end portion, of the cam follower, which is brought in contact with the slope surface of the cam surface. Therefore, the cam follower is pushed and moved upward in an obliquely incline posture in some cases. Then, the following situation may arise. That is, a position, of the wiper, which is pushed and moved upward by being brought in contact with the cam follower is deviated, and thereby the wiper approaches to the liquid jetting surface in the obliquely incline posture. As described above, when the wiper approaches to the liquid jetting surface in an unstable posture in which the wiper is inclined in the tangential direction with respect to the rotating path of the rotary cam, various problems would be caused. For example, when the wiper is moved in the obliquely incline posture, the wiper would deviate from a moving path of a case in which the wiper is moved upright without being inclined obliquely. As a result, the wiper would come into contact with surrounding constitutive parts or components, thereby damaging the wiper and the constitutive parts or components brought in contact with the wiper.
Further, in the ink-jet printer described in Japanese Patent Application laid-open No. 2005-246929, the wiper is required to be arranged directly above the rotary cam; and the wiper and the rotary cam are required to be arranged as a pair in a design of the ink-jet printer. Thus, the ink-jet printer described in Japanese Patent Application laid-open No. 2005-246929 is more likely to be subject to restriction of the arrangement, thereby decreasing degree of freedom of the arrangement of the wiper.